高频GPS测定的尼泊尔Mw7.8和Mw7.3地震震时地表动态变形过程

摘要

以陆态网络和尼泊尔境内高频(1 Hz)GPS观测数据为基础,采用动态双差相对定位方法,获取2015年尼泊尔Mw7.8和Mw7.3地震震时近场地表动态变形过程.结果表明,Mw7.8地震震中东侧高频GPS站动态位移幅度明显大于震中西侧;各高频GPS站动态位移幅度不仅与测站震中距有关,而且与地震破裂传播方向有关;Mw7.3地震引起的水平动态位移相对较小.将高频GPS与邻近强震仪动态位移时序进行对比发现,二者在振幅和相位上具有较好的一致性.%We derive dynamic ground deformations caused by the 2015 Nepal Mw7.8 and Mw7.3 earthquakes on the basis of 1 Hz GPS data of crustal movement observation network of China (CMONOC) and Nepal using kinematic relative positioning method.The results show that the displacement amplitudes of eastern GPS sites of the Mw7.8 earthquake are larger than the western.The kinematic deformations of each station arenot only associated with epicentral distance but also earthquake rupture propagation directivity.Dynamic ground motions caused by the Mw7.3 earthquake are small.We find good agreement between high-rate GPS and strong motion displacements time series.